Transesterification Of Oil Research Articles

Kinetics and thermodynamics in microwave-assisted transesterification of palm oil utilizing sulphonated bio-graphene catalysts for biodiesel production

Enhanced reaction performance is what has piqued interest in using graphene-based catalysts in producing biodiesel. However, in-depth analyses were lacking from a kinetic and thermodynamic standpoint. This means that a well-designed experiment is necessary to determine the effect that the graphene catalysts have on the reaction rates and yields. This work addresses the kinetic and thermodynamic aspects of heterogeneously catalyzed transesterification using sulphonated biomass-derived graphene catalysts, i.e., bGO-SO3H and brGO-SO3H. It was accomplished using the pseudo-first order mechanism and the Eyring-Polanyi equation, with all data fitting satisfactorily in both models at the ideal reaction temperature of 353.15 K, resulting in R2 values of 0.9784 (bGO-SO3H) and 0.9884 (brGO-SO3H). The calculated activation energy (Ea) was determined to be 44.45 and 51.73 kJ mol-1 for bGO- and brGO-SO3H, respectively. Additionally, the Gibbs free energy (ΔG) values were determined at −38.09 and −31.81 kJ mol−1 for bGO- and brGO-SO3H, respectively. Meanwhile, the values for ΔH and ΔS were obtained as 41.69 kJ mol−1 and 225.93 J mol−1 K−1, respectively, and 48.96 kJ mol−1 and 228.72 J mol−1 K−1, respectively. These collective outcomes collectively signify the endothermic nature of the reaction and their spontaneity, particularly under elevated temperature conditions.

Biodiesel synthesis through Gossypium hirsutum oil transesterification using reusable nanocatalysts: An energy intensive approach optimization

The present study intends to synthesize biodiesel from Gossypium hirsutum (cottonseed) oil using reusable copper (Cu) nanoparticles and optimize the transesterification process parameters to achieve a higher yield of Gossypium hirsutum biodiesel (GHB). The Cu nanoparticle was synthesized through the polyol method, and its fundamental characteristics were analyzed using scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. The cottonseed oil, obtained through mechanical expeller, was then subjected to a two-step transesterification process for the conversion into GHB. Key process parameters such as Cu catalyst concentration (CuC), methanol-oil-ratio (MOR), and reaction time (RT) were optimized at a reaction temperature of 60 °C. The GHB’s elemental composition, Fourier-transform infrared spectroscopy, and physicochemical properties were analyzed. The results indicate that the nanoparticle characterization provided valuable insights into its properties, showcasing its recyclability for five consecutive cycles. The optimized process parameters for achieving a higher GHB yield were determined as CuC of 211 ppm, MOR of 8.5, and RT of 104.5 minutes, resulting in GHB yield of 95.6%. Furthermore, an exploration of an energy-intensive approach revealed that a slight reduction in CuC by 1% and an increase in the MOR by 2.4% significantly reduced the RT by 36.3%, with only a marginal decrease in GHB yield (2.6%). Confirmation experiments validated the predicted values, and the fuel properties of GHB strongly support its efficacy as a valuable fuel source.

Eco-Friendly Approach to Palm Oil Biodiesel Production: Torrefied Palm Frond Carbon as a Source for CaO/C/NaOH Catalysts

Biomass-based sources for energy generation have attracted much attention recently due to its environmental benefits. These days, using edible oils and alkali catalysts, such as CaO, is standard practice for the transesterification step of the biodiesel synthesis process. Glycerine and methanol will form hydrogen bonds with the oxygen ions on the CaO surface, increasing the viscosity of the glycerine and causing CaO to suspend. Even though CaO was utilized directly as a catalyst in the transesterification process, extracting the CaO and glycerine from the final product will be challenging. To solve this issue, any extra metal oxides or catalyst supports ought to be impregnated into the CaO. This work has investigated the possible use of eggshells and palm fronds in developing bifunctional catalysts for biodiesel production. A series makes the processes' catalyst, including impregnation, calcination, and torrefaction. To assess the catalyst's performance, the esterification and transesterification of palm oil with a 2.9% free fatty acid content were investigated at a methanol/oil ratio of 6:1, catalyst concentration of 1-3% by weight, reaction temperature of 70 °C, and duration of 3 hours. The catalyst was found to have a specific surface area of 8.266 m2/g. There was an 89.4% yield of biodiesel produced. A viable, economical, and ecologically friendly method of producing biodiesel is to use eggshells and palm fronds in catalyst synthesis.

Rebiopolyols – New components for the synthesis of polyurethane biofoams in line with the circular economy concept

The primary goal of the research presented here was to evaluate the possibility of chemolysis of polyurethane biofoams synthesized from vegetable oil-based biopolyols with different chemical structures. As a reference material, a foam synthesized in 100 % from a petrochemical polyol was used. Chemolysis of polyurethane foams was conducted by using diethylene glycol as a solvent with a 1.5:1 wt ratio of biopolyurethane scraps to glycol. The reaction was carried out at 180 °C for 100 min in the presence of potassium hydroxide as a catalyst. The results of the chemolysis of different polyurethane foams were evaluated in terms of the hydroxyl number, amine value, viscosity, molecular weight and FTIR analysis of the new rebiopolyols. It can be concluded that the chemical structures of different biopolyols (obtained through the method of transesterification of vegetable oils with two different reagents and a two-step method of epoxidation and oxirane rings opening) that are used to make biopolyurethane foams have an impact on the course of the chemolysis process and the properties of resultant rebiopolyols.In order to verify the application possibilities of the new components obtained in accordance with the idea of circular economy, extreme conditions were applied in the form of complete replacement of the polyol in the reference foam with the rebiopolyols. It was found that replacing the petrochemical polyol with the repolyol results in partial cell opening, and replacing this component with the rebiopolyols results in open-cell foams. Only the rebiopolyol derived from the biofoam with the biopolyol obtained by transesterification of oil with triethanolamine was not suitable for use in a polyurethane system because its reactivity was too high. In conclusion, there is no need to use catalysts to obtain new biofoams from rebiopolyols given the catalytic nature of the new biocomponents.

Revisiting the Potential of Group VI Inorganic Precatalysts for the Ethenolysis of Fatty Acids through a Mechanochemical Approach.

The utilization of biobased feedstocks to prepare useful compounds is a pivotal trend in current chemical research. Among a varied portfolio of naturally available starting materials, fatty acids are abundant, versatile substrates with multiple applications. In this context, the ethenolysis of unsaturated fatty acid esters such as methyl oleate is an atom-economical way to prepare functional C10 olefins with a biobased footprint. Despite the existence of a variety of metathesis catalysts for the latter process, there is a lack of readily available, efficient, and inexpensive catalytic systems based on earth-abundant metals (Mo, W) whose preparation does not require sophisticated syntheses and manipulations. Here, a systematic exploration of homogeneous and heterogeneous inorganic Mo, W (oxy)halides shows that MoOCl4, while inactive as a homogeneous species, forms active and selective silica-supported ethenolysis precatalysts able to reach equilibrium conversion of methyl oleate within a few minutes upon activation with SnMe4. Such heterogeneous MoOCl4-based precatalysts were easily accessed through mechanochemical solvent-free procedures and found to contain, upon characterization by elemental analysis and Raman spectroscopy, isolated (≡SiO)Mo(=O)Cl3 units or polymeric silica-supported [-O(≡SiO)nMoCl4-nO-]m (n = 1, 2) complexes depending on the molybdenum loading. The former isolated species exhibited a higher catalytic performance. The developed heterogeneous precatalysts could be applied to the ethenolysis of various substrates, including polyunsaturated fatty acid esters and industrial fatty acid methyl ester (FAME) mixtures from palm oil transesterification.

Preparation of biodiesel by transesterification of castor oil catalyzed by flaky halloysite supported ZnO/SnO2 heterojunction photocatalyst

Biodiesel belongs to renewable energy and is a potential substitute for petrochemical diesel. In this study, ZnO/SnO2@halloysite heterojunction photocatalyst was prepared by loading semiconductor zinc oxide and tin dioxide on layered kaolin by the improved wet calcination method, which was used to photocatalytic the transesterification of castor oil and ethanol to produce biodiesel. TG-DTG, BET, XRD, UV–vis and SEM-EDS were used to characterize the composition, specific surface area, light absorption characteristics and photocatalytic performance of the samples. The reaction conditions were optimized by the Taguchi method. The optimum reaction conditions were as follows: catalyst dosage 4 wt%, molar ratio of ethanol to oil 12:1, reaction temperature 75 °C. After 2 h, the yield of biodiesel was 96.75 %. In the study of catalyst reusability, the yield of biodiesel is still above 85 % after being reused for 5 times. The kinetics of photocatalytic transesterification was studied, and the results accorded with quasi-first-order kinetics. The activation energy was 75.02 kJ/mol. Lastly, an eight-step reaction mechanism of photocatalytic transesterification was proposed. The prepared castor oil biodiesel can be prepared into B20 biodiesel through additives or mixing to meet ASTM D6751 and EN 14214 standards.

Synthesis of a Highly Efficient Mesoporous Green Catalyst from Waste Avocado Peels for Biodiesel Production from Used Cooking–Baobab Hybrid Oil

Valorization of waste biomass materials for fuels and other energy products has become one of the effective ways of escalating and improving the bioeconomy. The development of a novel biomass solid catalyst obtained from waste avocado peels and its potentials in transesterification of a bi-hybrid oil of used cooking–baobab oil (UC-BO) was investigated in this study. The catalyst was produced by calcining the burnt char of the dried avocado peels. The produced calcined avocado peels catalyst (CAP) was further characterized using analytical equipment, such as FT-IR, XRD, SEM, EDX, and TGA, to ascertain its catalytic properties. The results revealed that CAP contains some vital elements, such as Mg, P, Cl, Ca, Si, Na, and a high percentage of K content, present in form of oxides, carbonates, chlorides, and mixed metal compounds. The catalyst displayed effective catalytic potential in converting the UC-BO to biodiesel with 100% yield under an optimized condition of 51 min reaction time (RT), 14.5:1 of methanol to oil ratio (MTOR), and 2.73 wt% of catalyst loading (CL) at a constant temperature of 60 °C. The CAP exhibited excellent recyclability potential, achieving 92.85% biodiesel yield after five successive reaction cycles without notable catalytic activity reduction. The fuel properties investigated were all established within the biodiesel quality specifications of EN 14241 and ASTM D6751, demonstrating that it is a practical substitute for petroleum fuel.

Thermostable CaCO3-Immobilized Bacillus subtilis Lipase for Sustainable Biodiesel Production from Waste Cooking Oil

Due to the increasing demand for green processes in renewable energy production, the extracellular Bacillus subtilis B-1-4 lipase was used as a biocatalyst for producing biodiesel from waste cooking oil. Response surface methodology was employed for the optimization of enzyme production. Lipase activity was modeled with a quadratic function of four factors that primarily influence the culture medium. Thanks to this model, an optimal lipase activity of 1.7 ± 0.082 U/mL was achieved with the best culture medium composition: 16 g/L of tryptone, 15 g/L of yeast extract, 15 g/L of NaCl, and a 0.15 initial optical density at 600 nm (OD600 nm). The maximal lipase activity was measured at 45 °C and pH 8, using para-nitrophenyl palmitate as a substrate. The enzyme maintained above 94% and 99% of its initial activity at temperatures ranging from 40 to 50 °C and at pH 8, respectively. Moreover, it exhibited a higher residual activity than other Bacillus lipases in the presence of organic solvents. Residual activities of 86.7% and 90.2% were measured in the presence of isopropanol and ethanol, respectively. The lipase was immobilized by adsorption onto CaCO3 powder. FT-IR and SEM were used to characterize the surface-modified support. After immobilization, a lipase activity of 7.1 U/mg of CaCO3 was obtained. Under the optimized conditions, the highest biodiesel yield of 71% was obtained through the transesterification of waste cooking oil using the CaCO3-immobilized Bacillus subtilis lipase. This research reveals a method for the utilization of waste cooking oil for biodiesel production using an efficient immobilized thermostable lipase, providing environmental and economic security.

Microwave-assisted transesterification of sour cherry kernel oil for biodiesel production: comparison with ultrasonic bath-, ultrasonic probe-, and ohmic-assisted transesterification methods

In this study, sour cherry kernel oil was converted to biodiesel by microwave-assisted transesterification. Evaluations were made of several variables, namely, reaction time (1, 2, 3, 4, and 5 min), microwave power (100, 200, 300, 400, and 500 W), methanol/oil mole ratio (3, 6, 9, 12, and 15), and catalyst (KOH) concentration (0.3%, 0.6%, 0.9%, 1.2%, and 1.5%). The efficiency of fatty acid methyl esters increased in response to lengthier reaction times, greater microwave power, higher methanol/oil mole ratio, and higher catalyst concentrations up to the optimal level. The optimal reaction conditions for microwave-assisted transesterification were 300 W microwave power, 1.2% catalyst concentration, a methanol/oil mole ratio of 1:2, and a reaction time of 4 min. Microwave-assisted transesterification was more effective than ohmic-, magnetic stirrer-, ultrasonic probe-, and ultrasonic bath-assisted transesterification methods. In conclusion, microwave-assisted transesterification can be suggested as a fast, efficient, and economical method compared to other transesterification methods.

Sustainable microwave-supported biodiesel production using sandbox oil and its waste shell as a nanoparticle green alkali heterogeneous catalyst

This present work explored the possible use of sandbox seed (Hura crepitans) shell (SSS) waste as a feedstock for synthesizing green solid alkali biocatalyst in the microwave-aided sandbox oil (SBO) transesterification to obtain SBO biodiesel (SBOB). The solid catalyst was produced using a calcination method by burning raw SSS in the open air to obtain ash heated for 3 h in a furnace at 500 °C. The calcined sandbox shell ash (CSSA) produced was characterized using standard techniques to establish its catalytic potency. Also, a model was developed to simulate the process and examine the interactive effect of process input variables on SBOB yield using the Taguchi approach. The CSSA characterization showed it composed of K (44.99 %), Ca (1.54 %), and Mg (1.87 %) with crystalline compounds of K and Mg. The physisorption results gave a mean pore size of 18.142 nm and a surface area of 6.1125 m2/g. The best combination of the input variables determined for the process is a heating power of 450 W, methanol:SBO of 8:1, time of 1.5 min, and CSSA loading of 2 wt% with an optimum SBOB yield of 98.27 wt%. The SBOB produced met standard specifications for biodiesel. Microwave application to the SBO transesterification aided in rapidly completing the reaction. The study concluded that sandbox seeds and their shells are promising feedstock for cheap and sustainable biodiesel production.

Unjuk kerja mesin diesel berbahan bakar biodiesel campuran jatropha – sawit 4 : 1

The increasing need for energy and environmental problems caused by the use of fossil fuels make the development of alternative fuels very important. This research aims to explore the potential of a jatropha-palm biodiesel combination with a 4:1 composition as an alternative fuel. The methods employed include esterification and transesterification of both oils, along with physical property testing and diesel engine performance. Results indicate an increase in density and viscosity with increasing biodiesel concentration, while the calorific value decreases. The fuel injection angle also changes with a higher biodiesel proportion. The diesel engine exhibits variations in rotational speed and power depending on the load and type of fuel. Specific Fuel Consumption (SFC) increases with engine load. In conclusion, the jatropha-palm biodiesel combination holds potential as an alternative diesel engine fuel.

Modelling and optimization of luffa oil transesterification via acid activated waste marble catalyst

This study assessed the performance of response surface methodology (RSM) and artificial neural network (ANN) in modelling the transesterification of luffa oil using acid activated waste marble catalyst. The waste marble was activated with 0.5 molar sulphuric acid at 600 oC for 4 hours and was characterized by SEM, FT-IR, XRD, XRF, and BET; the characterization proved that the catalyst was successfully activated. The experiments were conducted at a catalyst dosage (1-5 wt. %), temperature (40-80 oC), methanol-oil ratio (4:1-12:1), time (1-3 hours), and agitation speed of (100- 500 rpm) with output as biodiesel yield. ANN was assessed using three back-propagation (BP) procedures, each comprising five neurons (input layer), one (output layer) and ten (hidden layer). The Levenberg Marquardt technique offered the most accurate prediction for luffa oil transesterification. The models were developed based on experimental and algorithm simulations and designs. The models' performance was assessed using the R2 and MSE. Regarding R2 and MSE, the ANN model (R2=9.9921E-1, MSE=0.06311) has a superior predictive capacity in forecasting the process than the RSM (R2=0.9885, MSE=0.86). At a catalyst concentration (3wt %), time (2 hours), temperature (60 oC), agitation speed (100 rpm) and methanol-oil ratio (12:1), the experimental (92.57 %), RSM predicted (94.0487 %) and ANN predicted (91.1768 %) biodiesel yield showed an agreement between the experimental and predicted values. The findings via physicochemical analysis, FT-IR, and GC-MS confirm that the biodiesel was within ASTM specifications.

Effective transesterification of castor oil to biodiesel catalyzed by novel carbon-based calcium composite

A novel carbon-based calcium catalyst was prepared through impregnation-calcination method, and was successfully applied as an effective catalyst for transesterification of castor oil to produce biodiesel. The catalyst prepared through the calcination at 500 °C for 3 h (Ca/C-500–3) exhibited the optimal performance. The prepared carbon-based calcium catalyst had excellent crystallinity and morphology, high basicity and surface area according to the characterization analysis results. Based on the XPS analysis, the combination of CaO and C in Ca/C-500–3 could improve the oxygen ion donating ability, which was beneficial for the reaction of triglycerides with methanol. The optimum composite of carbon-based calcium catalyst (Ca/C-500–3) displayed the excellent catalytic activity in castor oil transesterification, and 95.44 % of biodiesel conversion was obtained with the following conditions: methanol to oil molar ratio of 18:1, catalyst dosage of 5 wt%, reaction temperature of 65 °C and reaction time of 3 h. The TOF indicated that Ca/C-500–3 was an efficiency catalyst. Meanwhile, the calculation results of E-factor and PMI manifested that the transesterification of castor oil to biodiesel catalyzed by Ca/C-500–3 was a green reaction. Ca/C-500–3 could retain its high catalytic activity after five reaction cycles. The LCC cost analysis results suggested that, using Ca/C-500–3 as catalyst, biodiesel production from castor oil as feedstock had lower production cost compared to other biodiesel productions. The various factors affecting the cost of producing biodiesel were investigated using sensitivity analysis. Finally, the possible mechanism of catalytic transesterification reaction using carbon-based calcium composites was revealed.

Biocatalytic transesterification of salmon oil in ionic liquid media to obtain concentrates of omega-3 polyunsaturated fatty acids

In this study, a biphasic system combining oil and ionic liquid was utilized for lipase-catalyzed transesterification of salmon oil and alcohol to concentrate n-3 PUFAs, notably EPA and DHA. Various process variables, such as enzyme type, quantity, alcohol chain length, temperature, reactant proportions, and ionic liquid selection, were systematically assessed to optimize the process and enhance the yield of these valuable fatty acids. It was found that the Novozym 435 and Lipolase 100L Type EX emerged as the most effective enzymes. The impact of varying alcohol chain lengths (C1–C8) was examined, revealing that the Novozym 435 enzyme displayed its peak synthetic activity with 2-propanol. The results revealed a substantial increase in the overall activity during the transesterification reaction when employing ILs featuring hydrophobic cations and anions with low nucleophilicity. Specifically, the [omim+][NTf2−] ionic liquid exhibited the highest level of activity. This research holds promise for more efficiently and sustainably obtaining concentrated n-3 PUFAs from fish oil while reducing environmental impact relative to other existing concentration processes.

Improvement of waste frying oil/cottonseed oil-based biodiesel properties by adjusting unsaturation and its effect on engine emission characteristics

Waste frying oil is a highly promising feedstock for biodiesel production due to its lower cost compared to refined vegetable oils. In this study, biodiesel was prepared by transesterification of mixed waste frying oil with dimethyl carbonate, utilizing immobilized recombinant lipase in tert-butanol as the medium. The activation energy (Ea) and pre-exponential factor (k0) were determined to be 73.8 kJ/mol and 1.62×106, respectively. Under optimal reaction conditions, the biodiesel yield can reach 88.5%. Subsequently, cottonseed oil was introduced into the feedstock to enhance the crystallization temperature of the product, which enables biodiesel production to meet the fuel property standards. The cold filter plugging point of biodiesel was reduced to 4.3 ℃. Ultimately, blending biodiesel with diesel significantly reduces smoke emissions from diesel engines, with the B80 blend demonstrating superior effectiveness. This study presents an efficient and cost-effective method for biodiesel production.

Indirect Measurement of Variables in a Heterogeneous Reaction for Biodiesel Production.

This research focuses on the development of a state observer for performing indirect measurements of the main variables involved in the soybean oil transesterification reaction with a guishe biochar-based heterogeneous catalyst; the studied reaction takes place in a batch reactor. The mathematical model required for the observer design includes the triglycerides' conversion rate, and the reaction temperature. Since these variables are represented by nonlinear differential equations, the model is linearized around an operation point; after that, the pole placement and linear quadratic regulator (LQR) methods are considered for calculating the observer gain vector L(x). Then, the estimation of the conversion rate and the reaction temperature provided by the observer are used to indirectly measure other variables such as esters, alcohol, and byproducts. The observer performance is evaluated with three error indexes considering initial condition variations up to 30%. With both methods, a fast convergence (less than 3 h in the worst case) of the observer is remarked.

Calcined Biowaste Durian Peel as a Heterogeneous Catalyst for Room-Temperature Biodiesel Production Using a Homogenizer Device.

Calcined biowaste durian peel (BDP) contains 86% potassium element as the main compound and has successfully catalyzed the transesterification of palm oil to biodiesel at room temperature. The effect of catalyst weight, molar ratio of palm oil to methanol, reaction time, and rotational speed of the homogenizer device was investigated on biodiesel conversion and yield. The highest biodiesel conversion of 97.4 ± 0.3% was achieved using the following reaction conditions: a catalyst weight of 5 wt %, a molar ratio of palm oil to methanol of 1:15, a reaction time of 10 min, and a rotational speed of 6000 rpm. Unfortunately, calcined BDP could not hold its catalytic activity in the reusability study. The biodiesel conversion was decreased in the second cycle due to the decrease of both catalyst weight and concentration of potassium ions after the first cycle. However, the calcined BDP paired with a homogenizer device could produce biodiesel in a short reaction time and at room temperature.

Synthesis of biodiesel from the composite oil and process parameters optimization using artificial neural network

This study aims to investigate the effect of catalyst utilization (wt%), methanol to composite oil molar ratio (mole) and reaction thermal state (°C) on the biodiesel yield percentage of transesterification of novel composite oil (equal volume % of Castor oil, Mahua oil and dairy waste scum oil). Artificial neural network (ANN) based on central composite design was implemented to investigate the influence of catalyst utilization (1–3 wt%), methanol to composite oil molar ratio (6–12 molar) and reaction thermal state (55–65 °C) as the independent variables. Levenberg-Marquardt algorithm was used to predict the responses, biodiesel yield %. The fairness of the ANN prediction of biodiesel yield % is tested by means of coefficients of determination of training phase, validation set, test set and combined training, validation and test. The results revealed that the optimum catalyst utilization, methanol to composite oil molar ratio and reaction thermal state were determined as 3 wt%, 9 molar, and 65 °C for the maximum biodiesel yield of 94 ± 1% from the composite oil. The ASTM D6751 standard is employed to assess the quality of biodiesel derived from a blend of oils. The findings of this study indicate that the newly developed mixed oil is a viable feedstock for the production of biodiesel.

Supported sodium aluminate catalysts effectively catalyze biodiesel synthesis

Strongly basic sodium aluminate (NaAlO2) was supported on titanium dioxide, γ-alumina, and hydrotalcite by impregnation. The resulting catalysts showed improved specific activity in the transesterification of sunflower oil in methanol, as compared to the unsupported NaAlO2. Even with small sodium aluminate loading (i.e. 2.3% up to 9.4%) valuables fatty acid methyl esters (FAME) yields can be obtained. In particular, 9.4SA-HT shows the best catalytic activity achieving a 70% yield after 240 min of reaction, with a mere catalyst loading of 1.5% wt (with respect to the oil mass) in the reaction media. Innovatively, a detailed correlation between the amount, strength, and nature of the basic sites and the support type is proposed. In particular, it is demonstrated that only a part of the basic sites is effectively available for catalysis because of the already adsorbed atmospheric CO2. Thus, a combination of effective availability and strength of the active species is pivotal for a high catalytic performance in the synthesis of biodiesel from triglycerides.

Measuring risk of renewable diesel production processes using a multi-criteria decision strategy

This study proposes measuring the risk of five alternative renewable diesel production technologies using a multi-criteria decision matrix strategy. Evaluated criteria include environmental, economic, technological, social, and process safety risks. The subjective Analytical Hierarchy Process (AHP) with stakeholder input provides criteria and sub-criteria weightings and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) ranks alternatives. Alternative renewable diesel options are Green Diesel from first, second, and third-generation feedstocks, Fischer-Tropsch Diesel from second-generation biomass, and the transesterification of vegetable oils (VO) to make biodiesel. This study is a response to an earlier work measuring the sustainability of the same renewable technologies. While the previous work indicated Fischer-Tropsch Diesel as the most sustainable, this current work indicated the process as the “most risky,” suggesting that risk is a significant driver of decision making over sustainability, and newly developed decision tools should address both perspectives.